VPN Tunneling Multicast Support

To enable streaming IP video broadcasts over the internal network, VPN tunneling features Internet Group Management Protocol (IGMP) gateway multicast proxy support.

VPN tunneling does not support IGMP v2. If you are using VPN tunneling multicast support, and you are using L2 switches, make sure the switches support IGMP v3.

When users initiate a request to join a multicast group, the system initiates an IGMP join message to the local multicast router or switch on the client's behalf. In addition, the system stores the IGMP group request queries in its cache so that whenever a multicast router in the network polls the system for IGMP group information, it responds with its current collection of multicast user and group requests. If a router or switch does not receive a response from the system, the system's multicast group information is removed from the router or switch's forwarding table.

VPN tunneling supports streaming media at up to 2 mbps on a single tunnel (megabits per second).